Check out the graph here, generated from the Vostok Ice Core samples:
http://www.grida.no/climate/vital/02.htm
The neat thing is that the last three interglacial warm periods were warmer than the one we're in now, sometimes by over 2 degrees C.
We should check those periods in time to see if there was massive biological damage during the hot times. Then we'll know if we're really in danger now.